制备了一种用于生化需氧量检测的新型微生物传感器,选用玻碳电极为基底电极、海藻酸钠(SA)改性的聚乙烯醇(PVA)凝胶为微生物包埋载体、地衣芽孢杆菌为固定化微生物,将氧化还原介体中性红(NR)电聚合到微生物细胞表面形成聚中性红(PNR),并对传感器电化学性能进行了探究。结果表明,与微生物敏感膜内细胞结合的PNR能有效保持氧化还原性能,从而促进微生物与电极表面的电子转移。该电极在4~24 mg/L BOD标准溶液中呈现良好的线性响应性能,检出限2 mg/L(S/N=3),响应时间400 s。固定化微生物存活率80%以上,最适酸碱环境为中性,最适温度为35℃。微生物传感电极在2个月内保持着良好的稳定性。

A novel electrochemical microbial sensor is prepared for the detection of biochemical oxygen demand.Taking glassy carbon electrode as the substrate electrode,sodium alginate (SA) modified polyvinyl alcohol (PVA) gel as a microbial carrier,bacillus licheniformis as the immobilized microorganism,and neutral red as a redox mediator is polymerized onto the surface of microbial cells to form polyneutral red (PNR).The electrochemical performance of the sensor is studied.Results show that PNR combined with cells in microbial sensitive membrane can effectively maintain redox performance,which can promote electron transfer between microorganisms and electrode surface.The electrode shows good linear response in 4-24 mg·L^-1 BOD standard solution,with a limit detection of 3 mg·L^-1 (S/N=3) and a response time of 400 s.The survival rate of immobilized microorganisms exceeds 80%.Neutral environment is the optimum for the immobilized microorganisms and the optimum temperature for the immobilized microorganisms is 35℃.This microbial sensing electrode has maintained a good stability in two months.